Mounting for incandescent lamps of railway light signals



Fl ca. 1.

Oct. 20, 1925. 1,558,386

E. w. MOORE MOUNTING FOR INCANDESCENT LAMPS OF RAILWAY LIGHT SIGNALS Filed- Sept. 50, 1921 /a AHORNEY.

Patented Oct. 20, 1925.

UNITED STATES PATENT OFFICE.

. EDMUND W. MOORE, OF ROCHESTER, NEW YORK, .ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OF NEW YORK.

MOUNTING FOR IN-GANDESCENT LAMPS OF RAILWAY LIGHT SIGNALS.

Application filed September 30, 1921. Serial No. 504,456.

To all whom it may concern.

Be it known that I, EDMUND W. Moons, a citizen of the United States, residing at Rochester, in the county of Monroe and State of New York, have-invented certain new and useful Improvements in Mountings for Incandescent Lam s of Railway Light Signals, of which the following is a specification.

This invention relates to the structure of a mounting or support for electric lamps used in light projecting systems, and more particularly to the mounting for concentrated filament lamps employed in light signals for railway signaling purposes.

- In order to obtain visibility of signals for a long range and through a considerable angle of spread, during the day time as well as at night, and to maintain a desirable. low energy consumption, an efiicient light projectingunit is required. To accomplish these ends, besides well designed optical devices or light concentrating devices, such as reflectors, lenses, etc., it is necessary to have a concentrated light source properly located with respect to such optical devices. If the concentrated light source is an incandescent lamp which must be renewed from time to time, it is desirable to be able to make such replacements in the field conveniently, and at the same time have the replaced filament assume the same and proper relation with respect to the optical devices as that of the lamp replaced. Lamps manufactured in quantities on a commercial scale, however, do not have their filaments in any definite relation with respect to their bases, and consequently when lamps of this kind are used in connection with light concentrating devices and burn out, or are otherwise unfit for service and must be replaced, adjustments to properly focus them are required. Such adjustments of lamps in the field are a cumbersome and an expensive expedient, since at least two experienced workmen are required, one at the signal to change the adjustment, and the other at a distance to determine/from the appearance of the signal when the proper adjustment has been made. 2

\Vith the idea of obviating the necessity. of this procedure each and every time a new lamp is placed in service, it is pro'posed'in the. present invention-tofix up 'or rebas'e commercial lamps in such a way, that their base in the socket.

Other objects and purposes of the invention will appear as the description prorespective filaments will be accurately locat-' ed with respect to the optical device in which they are to be used when .the lamps are placed in service. I

On account of the importance of having the filament of the various lamps placed in a signal to come at the same and proper point, it is necessary to provide a suitable mounting for the lamp which will permit it to be quickly and easily detached and which will positively position the same. In order to accomplish these ends, it is further proposed in accordance with the present invention to employ a bayonet type socket, and to provide lamps of commercial manufacture with an auxiliary or supplemental base adapted to fit such sockets in such a way as to positively position the filaments of these lamps, regardless of reasonable variation of the size of parts incident to commercial manufacture, and likewise ermitting quick and easy detachment. ore specifically a concentrated filament lamp of commercial manufacture is provided with a supplemental sleeve over its cylindrical base having three pins corresponding to bayonet slots in a socket shell in which it is to be sup ported. Cooperation of the three pins with the hook shaped slots of the base results in athree-point support, thereby positioning the direction of the axis of the lamp regardless of the snugness of fit of the auxiliary gresses, and the novel features thereof will be pointed out in the appended claims.

In describing the invention in detail, reference will be'made to the accompanying drawings, in which Fig. 1 shows a concentrated filament lamp illustrated as having one assumed commercial inaccuracy in the location of its fila-- ment;

Fig. 2 shows one form of supplemental base embodied in the present invention;

Fig. 3 illustrates another form of supplemental base;

Fig.4 shows the supplemental base illustrated in Fig. 3 applied to the lamp illustrated in Fig. 1; and

. Fig. 5fshows a light projecting unit andthe. rebase'd lamp contained therein, both of which are constructed in accordance withv the present invention.

spectively.

One specific form of light projecting unit has been illustrated in Fig. 5 to explain the importance of having the filament of a lamp properly located with respect to its base, and consequently with respect to an optical unit, such as a lens. A portion of a casing 1 is shown having a circular opening provided with a lens seat, in which rests a lens 2. This lens is held in place by a retaining ring 3 secured to the casing by screws 4, and

extending considerably below the lens 2.

A gasket of felt or similar material is preferably interposed between the edge of the lens and the casing 1, but the retaining ring 3 bears directly against the lens. To this retaining ring 3 an angle bracket 5 is fastened by bolts 6, and on this bracket is fixedly supported a lamp receptacle consisting of a porcelain base 7 and a socket shell 8, provided with a plurality of bayonet slots of the usual shape forming hooks. This socket shell 8 is held firmly against the porcelain base 7 by theplate 11 and screws 12. In the center of the base is a metallic socket member 13, in which is slidably mounted a plunger 14, which is resiliently held up ward by a helical spring 15. The head of the plunger 14 is held withinthe socket member 13 by a conducting plate 16, which is held in place by a screw 17. Both the plates 11 and 16 are provided with a bind-I ing post 18 which serve to conduct current to the plunger 14 and socket shell 8 re- In the manufacture of these light projecting units, the socket shell 8 and its slots are definitely located with respect to the lens 2 by a standard jig or fixture used during their assemblage.

In Fig. 1 there is shown one typical form of incandescent lamp adapted to be used in connection with the present invention. Such lamps when manufactured on a large scale commercially, frequently have their filaments inaccurately located with respect to the bases of the lamps, and in the lamp shown it is assumed for the purpose of explanation that the stem supporting the filament'is tipped to one side of the axis of the base. In the particular form of lamp illustrated, the filament comprises two parallel convoluted filaments 19, both attached to the usual lead-in wires so that both filaments are normally lighted, one serving as a reserve when the other burns out. The lamp is provided with a plain cylindrical base 20 of the single contact type without threads or pins. Since it is desirable to use lamps interchangeably in a light projecting unit, such as illustrated in Fig. 5, and in each instance have the concentrated filament of the lamp come at the proper point with respect to t e lens or other optical device of said unit; andrsince lamps of commercial manufacture do not have their filaments accurately located with respect to their regular bases, as illustrated in Fig. 1, it becomes apparent that commercial lamps should be. fixed up in 'some suitable way so that their filaments, regardless of irregularities in their location with respect to the regular bases auxiliary or supplemental base be attachedto the usual base of commercial lamps in a manner to bring the filament in a definite relation to the supplemental base. The specific supplemental base embodying the present invention comprises a metallic sleeve 21 having an outside diameter to snugly fit the socket shell of the receptacle, leaving just sufficient clearance to allow for commercial inaccuracies in manufature, and having its internal diameter sufficiently larger than the cylindrical base of a commercial incandescent lamp, to permit it to be tiltably adjusted within the sleeve far enough totake care of ordinary inaccuracies in the location of the filament. In this sleeve are holes in which are riveted, soldered, or otherwise suitably fastened short radially projecting pins 22, these pins being adapted to fit in the bayonet slots of the socket shell 8. In practice the sleeve 21 is properly attached to the base 20 of the commercial lamp by placing the sleeve 21 and.lamp in a fixture, properly positioning the lamp filament 19 with respect to the sleeve'21, and then soldering the sleeve and lamp base together at two or more points, as illustrated at 23 in Figs. 4 and 5. After a standardized lamphas been provided in the manner above described, it is also important to 'provide a supporting structure for the lamp which will prevent tilting or sidewise displacement, in order that the filament will always be in the proper position, although the lamp may be carelessly tipped when inserted, or subjected to jar and vibration. With the usual bayonet type socket and base having two pins affording a two-point support, on acco'unt of the loose fit between the rebasing sleeve 21 and the socket shell 8 required for commercial manufacture it is evident that the lamp may tilt or rock about the pivot axis formed by the two pins; and while this movement. may be relatively small at the base of the lamp, it is multiplied at the filament, and may result in displacement of the filament from its proper position to an extent seriously interfering with the efficiency of a light projecting unit. In order to o pose this tilting movement of the lamp, t e

rebasing sleeve 21 in accordance with this lnvention is provided with resilient means rebasing sleeve 21 is made of brass, or other suitable material, so that these tongues 24 have the desired resiliency and stiffness The tongues are formed in the rebasing sleeve 21 before the lampis adjusted "and soldered therein, the adjustment of the lamp in the sleeve taking care of any slight variations that might exist in the shape or stiffness of said tongues. When the rebased lampis inserted in the socket shell 8, the spring tongues 24 engage this shell and hold the lamp in the proper position. These spring tongues 24 not only straighten up the rebasing sleeve 21 in the socket 8, so that no special care is required in putting in a lamp, but also resist any tendency .of the lamp to tilt. out of the proper position, due

to shock, vibration, or other causes.

These resilient tongues are formed on the rebasing sleeve 21, rather than on the socket shell 8, because the lamp may be-adjusted while the rebasing sleeve 21 is being applied to take care of any irregularities in these tongues 24; whereas, if the tongues 24 were formed on the socket 8, any irregularities therein would affect the position of all lamps put in that socket, and compensation for such irregularities would be a matter of considerable difficulty. Further, in case these tongues 24 are accidentally or carelessly bentout of shape, or broken off, the injury would, if the tongues 24 were on the sleeve 21, only affect the lamp in question, which could be discarded and another used in its place; whereas, if the tongues 24 were on the socket shell 8, the injury would be permanent and would have to be remedied before the signal could be used. Likewise, if the spring tongues 24 were formed on the socket shell 8, these tongues 24 would be subjected to bending and. distortion each time a new lamp is inserted, and in short, would have to stand up for the life of several lamps; whereas, the tongues 24 on the rebasing sleeve 21 are subjected to only one distortion when that particular lamp is put into service and need last no longer than the life of one lamp. I

Obviously, equivalent resilient,pr'ojections may be formed or attached to the sleeve in a way different from that shown-and described, and the particular form of the spring tongues shown is merely illustrative of the invention. V

I prevent positively any tilting of the lamp,

three radially extending pins 22 may be provided on the rebasing sleeve 21, as shown in Fig. 3. By this arrangement a three-point support is provided, thus supporting the rebasing sleeve 21 in a definite plane, thereby positively determining the direction of the axis of the'sleeve 21 with respect to the socket shell 8. Although by this arrangement no tilting of the lamp in the socket 8 is possible, sidewise movement of the sleeve 21 with respect to the socket 8 is still possible to the extent of the clearance between the sleeve 21 and-socket 8; and if desired, three spring tongues 24 disposed at points between the pins 22 may be formed in the sleeve, as shown in Fig. 3, in the same way as illustrated in Fig. 2. Since this sidewise movement is under ordinary conditions very small, the tongues 24 illustrated in Fig. 3 may be omitted.

In lamp mountings of this kind, it is important that the fiat side of the filament should face the optical device, such as the lens 2 in each instance. When a two-pinrebasing sleeve 21 is employed having its pins 22 diametrically opposite, one or the other of theflat faces of the filament 19 will face the optical device depending on how the lamp is inserted, which, although not an ideal construction, is satisfactory; but a .7

more precise arrangement may be provided, if desired, by disposing the two pins 22 unsymme'trica'lly, about the sleeve 21, thereby permitting the lamp to be inserted in one particular way only, that is, with the same side of the filament facing the optical unit as was determined when the rebasing sleeve 21 was applied. In order to permit the lamp provided with a sleeve 21 havingin the receptacle always hear the same rela tion to the opticalunit, it is onlv necessary when the rebasing sleeve 21 is applied to the lamp, to similarly locate the respective pins22 with respect to the filament 19 and thereby bring the fiat side of the filament 19 in position to face the optical unit.

From the foregoing it will be observed that this invention provides a lamp mount-- ing for railway light signals, which permits lamps to be easily and quickly put in signals by ordinary and unskilled labor, when required to replace those burnt out or otherwise rendered unfit for service, without requiring any speclal adjustment, andwithout likelihood'of beingwrong'ly placed by a careless workman.- The rebasing scheme does not alter regular methods of manufacturing lamps; but taking the lamps as made commercially, a-positive and permanent adjustment is made of the filament With relation to its supporting elements, namely, the sleeve 21 and pins 22, which not only locates the filament at the proper point when the lamp is put in a signal, butthe stem 26 is tilted toward the left, where of operation.

as in Fig. 5 the stem 26 of the lamp is in =alignment with the supplemental base 21,

but the bulb Q5 leans toward the right. It is to be understood that all the lamps will be-rebased according to the same standard, thereby permitting the lamps to be interchanged and in each instance have their filaments 19 located at the same facing in the same direction.

The practical'advantages ofemploying such standardized lamps will be evident upon comparison With the old scheme of adjusting each signal whenever a newcommercial lamp is put into service. In one case, the adjustment can be made in manufacture, with the aid of suitable tools and apparatus, assuring uniform and accurate results; whereas adjustments in the field are cumbersome and inaccurate, two workmen being required, one at the signal to make the adjustment, and anotherat a distance to determine from the appearance of the signal When the proper adjustment has been made. Difficulty is also encountered in practice in communicating the necessary in and also to make the manipulation of re-, placing lamps a practically fool proof performance,"

Having thus shown anddes cribe'd' several embodiments of the invention, it is to be understood that they do not exhaust the idea of means for carrying out this invention,

but merely illustrate their nature and mode What I claim, is

1. In a light signal, the combination with" lamp having a ase with three radial pins point and.

to fit in said socket, said lamp having a concentrated filament which is located in the same said predetermined relation to the axis of its base and the plane of its pins, whereby the filament of said lamp will come at the focal point of the optical unit without adjustment whenever the lamp is inserted in the socket, the spring pressed plunger of the socket co-acting with said pins and slots to constitute a three-point support which positions the lamp with the axis of its base in a definite angular relation'to the axis of the socket irrespective of mechanical clearance between the base and the socket. v I

2. In a light'signal, the combination with a lens, a lamp socket of the bayonet type having thnee slots and fixed in the position in which its axis and the plane of the closed ends of its slots bear a predetermined space relation to the focal point of said lens, an

incandescent lamp having a plain cylinrelation to the axis of the sleeve and -the plane of its pins, whereby the filament of the lamp is positioned at' the focal point of the lens whenever said sleeve is inserted in the socket irrespective of thelocation of the lamp filament relative to its base.

3; In a light signal, the combination with a lens, a bayonet type socket having three hook-shaped slots therein, the distanceflbeg tween two of said slots beingdifierentthan between either and the third slot, said socket having 'a plane ofthe-closed ends of its slots "located a predetermined fixedl dis'tance fromthe focal point of said lens, the axis of said socket passing througlrgsaid focal: point, a metallic sleeve with radially projecting pins spacedthe same as. said slotslandhaw but detachable fit in 'said-isocket, ari incandescent lamp having' 'a ,convoluted conce'ntrated filament anda' plain cylindrical base assemblediwith the usual manufacturing in-1 accuracies in the location of the filament with respect to the base, saidjlamp having its base soldered in sald sleeve in that particular endwise and'tiltedqposition;therein 11 5 inganv'external' diameter "to make a close v where the filament lies in the axis of the.

having t ree radially respective of the manufacturing curacies in its location relative to its base comes at the focal point of the lens and faces the lens when the lamp is inserted in said socket.

4:. In a device of the character described for supporting incandescent lamps of commercial manufacture in bayonet type sockets such that the filaments of said lamps in each instance have the same given space relation to said socket, the combination with an incandescent lamp having a convoluted concentrated filament and a plain cylindrical single contact base assembled with the usual manufacturing inaccuracies, a metallic cylindrical sleeve having an outside diameter to make a close but separable fit in the socket with allowances for variations in manufacture, said sleeve having fixed outwardly projecting radial pins spaced to enter the slots in the socket, said sleeve having an inside diameter larger than the outside diameter ofthe lamp base suflicient to permit tilting of the lamp base in the sleeve to the degree required to bring the filament in the axis of the sleeve irrespective of variations in the location of the filament with respect to the lamp base, said sleeve being soldered to the lamp base in that particular endwise and tilted relation sleeve with the ends of its filament in a line bearing a predetermined angular relation to the axes of said pins and where the fila'- ment is located a predetermined distance from the plane of the pins of the sleeve.

5. A light source for use in any one of a large number of light projecting devices each having a lens and a bayonet type socket fixed in position with its axis and slots in the same definite relation to the focal point of said lens, the combination with an incandescent lamp having two concentrated fila ments connected in parallel to the same lead-in wires and a plain cylindrical base assembled with the usual manufacturing irregularties in the location of the filaments with res set to the base, a metallic sleeve rojecting pins, the distance between two o said pins being different than the distance between either pin and the third in, said'sleeve being soldered on the base 0 the lam in that particular tilted and endwise relation thereto in which the filaments of the lamp has the same said definite relation to the axis of the sleeve and its pins as the axis of the socket and its slots has to the focal point of said 1ens,'whereby said lamp and sleeve can be inserted in any one of said socketsand will have its filament at the focal point of the associated lens.

6. In an opitical device, the combination of a lens, a bayonet tyfie socket providedwith slots unsymmetrica y spaced and havinacing a predetermined spacial relation to the lens; and a lamp in said socket provided with similarly spaced pins, and a concentrated filamentdefining a plane through the axis of the socket; said pins and plane of the'filament having a predetermined relation, thereby establishing a definite and predetermined relation between said filament and pins. a

7. A rebased incandescent lamp for use in light signals for railroads and the like which require accurate location of the fila-1 ments of the lamps therein with respect to the bayonet type socket supporting the lamp, comprising a relatively short convoluted filament constituting a concentrated source of light and a plain cylindrical base assembled on the bulb of the lamp with the usual manufacturing inaccuracies in the 10-.

cation of the filament with respect to the base, and means affording a cylindrical surface to fit in said socket and provided with three pins projecting radially with respect to the axis of "the base, said means being rigidly attached and electrically connected to said base in that particular relative posi-Y tion in which the filament is at a predetermined "distance from the plane of said pins and is in the axis of said cylindrical surface, the ends of said filament also being in a line bearing a predetermined angular relation to the axes of said pins.

8. A rebasing sleeve for attachment to electric lamps of the usual commercial manufacture provided with the usual metallic bases so as to afford an auxiliary base by Which the lamp may be supported in a socket with its filament in a definite relation thereto comprising; a metallic sleeve provided with a plurallty of external radially projecting pins, the inside diameter of said sleeve being larger than the outside diameter of the lamp base on which it is to be used, thereby permitting .the lamp base to be tilted in the sleeve sufli'cientlyto compensate for ordinary irregularities in filament location.

'9. A rebasing sleeve for attachment to electric lamps of the usual commercial ciently to compensate for ordinary irregularities in filament location.'

10. A rebasing sleeve for attachment to electric lamps of the usual commercial manufacture having the usual metallic bases i so as to afford an auxiliary base bywhich the lamp may be supported in a socket with its filament in a definite relation thereto comprising; a metallic sleeve having three external radially projecting unequally spaced pins, the inside diameter of said sleeve being larger than the outside diam eter of the lamp base on which'it is to be used, thereby permitting the lamp base to' be tilted. in the sleeve sufiiciently to compensate for ordinary irregularities in filament location.

11. A rebasing sleeve for attachment to electric lamps of the usual commercial manufacture having the usual metallic bases so as to afford an auxiliary base by which the lamp may be supported in a socket with its filament in a definite relation thereto comprising; a metallic sleeve having radially extending pins and provided with spring tongues extending beyond the outer surface of said sleeve and between said pins, the inside diameter of said sleeve being larger than the outside diameter of the lamp base on which it is to be used, thereby permitting the lamp base to be tilted in the sleeve sufficiently to compensate for ordinary irregularities in filament location.

12. A rebasing sleeve for attachment to electric lamps of the usual commercial manufacture so as to afiord an auxiliary base by which the lamp may be supported in a socket with its filament in a definite relation thereto comprising; a metallic slotted sleeve having radially extending pins and having the portion between adjacent slots bent outwardly, the inside diameter of said sleeve being larger than the outside diameter of the lamp base on which it is to be used, thereby permitting the lamp base to be tilted in the sleeve sufficiently to compensate for ordinary irregularities in filament location.

13. A' rebased incandescent lamp for use in light signals for railroads and similar light projecting devices which require accurate location of the light source, comprising a plain cylindrical single contact base and two convoluted concentrated filaments connected to the same lead-in .wires and assembled with the usual manufacturing irregularities in the location of the filaments with relation to the base, a metallic sleeve having three radially projecting pins and rigidly fixed and electrically connected to the base of the lamp in that particular adjusted position in which the filaments are a predetermined distance from the plane of ment with respect to the base, together with a supplemental metallic rebasing sleeve having three or more radially projecting pins and soldered to the base of the lamp in that particular endwise and tilted relation, in

which the filament, irrespective of its location relative to the lamp base, is positioned at a preselected distance from the plane of said pins and in a predetermined relation to the axis of said sleeve, said filament also having its ends positioned in a line bearing a predetermined angular relation to the axes of said pins.

'15. A rebased incandescent lamp for use in light signals for railroads and similar light projecting units which require accurate location of the light source, comprising a plain cylindrical single contact base and a concentrated filament assembled with the usual manufacturing inaccuracies, a metallic sleeve having three radially extending pins unequally spaced around the periphery of the sleeve, said sleeve being soldered on the lamp base in that particular endwise or tilted relation in which the filament is located at a predetermined distance from the plane of said three pins and in a predetermined relation to the axis of the sleeve, the ends of said filament also lying in a linehaving a predetermined angular relation to the axes of said pins.

16. A rebasing sleeve for attachment to electric lamps of the usual commercial manufacture so as to afford an auxiliary base by which the lamp may be supported in a socket with its filament in a definite rela-' tion thereto comprising, a metallic sleeve provided with a plurality of unequally spaced pins, and tongues between said pins extending outwardly from said sleeve to form spring fingers for resiliently centering.

said sleeve in such socket.

In testimony whereof I hereto alfix my signature.

EDMUND W. MOORE. 

